Concentric cells in a wireless communication system

ABSTRACT

Aspects described herein relate to a base station for providing air-to-ground wireless communication over various altitudes. The base station includes a first antenna array comprising one or more antennas configured to form a first cell coverage area extending substantially from a horizon up to a first elevation angle away from the first antenna array to a predetermined distance from the first antenna array. The base station further includes a second antenna array configured at an uptilt elevation angle to form a second cell coverage area extending at least from the first elevation angle to a second elevation away from the second antenna array, wherein the first cell coverage area and the second cell coverage area are concentric to define the ATG cell at least to the predetermined distance and up to a predetermined elevation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/934,620, filed on Jul. 21, 2020 which is a continuation of U.S.application Ser. No. 16/560,072 filed on Sep. 4, 2019, which is acontinuation of U.S. application Ser. No. 16/260,615 filed on Jan. 29,2019, which is a continuation of U.S. application Ser. No. 15/881,818filed Jan. 29, 2018, which is a continuation of Ser. No. 15/291,572filed Oct. 12, 2016 now granted as U.S. Pat. No. 9,924,378 which issuedon Mar. 20, 2018), which is a continuation of U.S. application Ser. No.15/002,609 filed Jan. 21, 2016 (now granted as U.S. Pat. No. 9,497,640which issued on Nov. 15, 2016), which is a continuation of U.S.application Ser. No. 14/689,335 filed Apr. 17, 2015 (now granted as U.S.Pat. No. 9,277,420 which issued on Mar. 1, 2016), which is acontinuation of U.S. application Ser. No. 13/832,752 filed Mar. 15, 2013(now granted as U.S. Pat. No. 9,014,704 which issued on Apr. 21, 2015),the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

Example embodiments generally relate to wireless communications and,more particularly, relate to employing concentric cells to providewireless communication at various altitudes.

BACKGROUND

High speed data communications and the devices that enable suchcommunications have become ubiquitous in modern society. These devicesmake many users capable of maintaining nearly continuous connectivity tothe Internet and other communication networks. Although these high speeddata connections are available through telephone lines, cable modems orother such devices that have a physical wired connection, wirelessconnections have revolutionized our ability to stay connected withoutsacrificing mobility.

However, in spite of the familiarity that people have with remainingcontinuously connected to networks while on the ground, people generallyunderstand that easy and/or cheap connectivity will tend to stop once anaircraft is boarded. Aviation platforms have still not become easily andcheaply connected to communication networks, at least for the passengersonboard. Attempts to stay connected in the air are typically costly andhave bandwidth limitations or high latency problems. Moreover,passengers willing to deal with the expense and issues presented byaircraft communication capabilities are often limited to very specificcommunication modes that are supported by the rigid communicationarchitecture provided on the aircraft.

Conventional ground based wireless communications systems use verticalantennas to provide coverage for device connectivity. Antennas used interrestrial systems typically provide coverage in the azimuthal, orhorizontal, plane with a width of 65 to 90 degrees. The elevation, orvertical, pattern is typically more narrow in order to maximize theantenna performance in the horizontal plane, which can result in alarger coverage area, increased signal strength or clarity in thecoverage area, etc. With focus on the horizontal plane, however, theseexisting antennas may be unable to support connectivity for aircrafttraveling above an elevation of the coverage area.

BRIEF SUMMARY OF SOME EXAMPLES

The continuous advancement of wireless technologies offers newopportunities to provide wireless coverage for aircraft at varyingelevations using multiple antennas installed at certain sites. A firstantenna array is provided at a cell site that can include one or moreantennas positioned at an angle and having a vertical beam width toprovide coverage at an elevation range over a related distance. A secondantenna array is also provided and positioned at a different elevationangle from the first antenna array to provide coverage for anotherelevation range over the related distance. In this regard, potentialcoverage gaps caused by the antennas of the first array near the cellsite can be covered by the second antenna array. Cells formed by thetransmitting first antenna array and second antenna array can beconcentric over the elevation, and can achieve a cylindrical coveragearea for air-to-ground (ATG) wireless communications extending to atleast to a desired elevation above, and/or a radial distance around, thecell site. Moreover, one or more patch antennas can be provided to forma cell within any coverage gaps over the cell site.

In one example embodiment, a base station providing ATG wirelesscommunication over various elevations of an ATG cell is provided. Thebase station includes a first antenna array comprising one or moreantennas configured to form a first cell coverage area extendingsubstantially from a horizon up to a first elevation angle away from thefirst antenna array to a predetermined distance from the first antennaarray. The base station further includes a second antenna arrayconfigured at an uptilt elevation angle to form a second cell coveragearea extending at least from the first elevation angle to a secondelevation away from the second antenna array, wherein the first cellcoverage area and the second cell coverage area are concentric to definethe ATG cell at least to the predetermined distance and up to apredetermined elevation.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 illustrates a top view and horizon view of an example desiredcylindrical coverage area for air-to-ground (ATG) wirelesscommunications;

FIG. 2 illustrates an aspect of an example system with an antennaconfiguration that provides at least the desired cylindrical coveragearea;

FIG. 3 illustrates a top view of an example coverage area provided bythe antenna configuration of FIG. 2 ;

FIG. 4 illustrates a functional block diagram of a base station of anexample embodiment; and

FIG. 5 illustrates an example methodology for providing concentric cellsto facilitate ATG wireless communications at desired elevations.

DETAILED DESCRIPTION

Some example embodiments now will be described more fully hereinafterwith reference to the accompanying drawings, in which some, but not allexample embodiments are shown. Indeed, the examples described andpictured herein should not be construed as being limiting as to thescope, applicability or configuration of the present disclosure. Rather,these example embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Like reference numerals may beused to refer to like elements throughout. Furthermore, as used herein,the term “or” is to be interpreted as a logical operator that results intrue whenever one or more of its operands are true.

Some example embodiments described herein provide architectures forimproved aircraft wireless communication performance. In this regard,some example embodiments may provide for base stations having antennastructures that facilitate providing wireless communication coverage invertical and horizontal planes with sufficient elevation to communicatewith aircraft at high altitudes. In this regard, while conventionalcellular networks need only concern themselves with coverage provided ina two dimensional (2D) environment, an air-to-ground (ATG) networknecessarily much account for a third dimension, namely altitude. Thus,to facilitate the provision of continuous 3D coverage over a desiredarea, example embodiments employ some structural changes to antennastructures to facilitate long reach of antennas while still achievingsuch reach to the operating altitudes at which aircraft operate.

In an example embodiment, multiple antennas may be positioned at varyingelevation angles on a base station to provide at least a 3D coveragezone (e.g., a cylinder of coverage) within which aircraft cancommunicate with the base stations a varying altitudes and regardless ofaircraft location with respect to the base station. In this regard, forexample, a first series of directional antennas may be oriented toprovide coverage of sectors to form 360 coverage around a base stationbetween the horizon and a first elevation angle. At least one additionalseries of directional antennas may be placed corresponding to theantennas of the first series but angled at a higher center elevation sothat the additional series of directional antennas covers an area atleast between the first elevation angle and some higher elevation angleto give a long reaching coverage range at the horizon that extends torelatively high altitudes.

In a specific example, a first antenna array can be provided tofacilitate wireless communications at least at a certain elevation rangefor a given radial distance across a horizontal plane. A second antennaarray can also be provided at uptilt elevation angles to facilitatewireless communications at another elevation range above the certainelevation range. The antennas can allow for concentric overlapping cellsthat provide a total coverage cell throughout the correspondingelevation ranges (and corresponding altitudes) at radial distances nearto and far from the base station. In addition, one or more patchantennas can be provided to facilitate wireless communications incoverage gaps over the base stations (e.g., directly above the basestations).

FIG. 1 illustrates a target area for base station coverage inair-to-ground (ATG) wireless communications. A top view 100 and a threedimensional horizon view 102 of a map of a southeastern portion of theUnited States are shown. In the top view 100, a base station (not shown)can provide the target area 104 by communicating over a plurality ofantennas to allow for communicating signals at a radial distance fromthe center of target area 104 and/or at an azimuth to cover at least thecircular boundaries defined by coverage area 104. It is to beappreciated that the effective base station coverage area can extendbeyond the circular coverage area 104, in one example; however, thecircular coverage area 104 can be a minimum coverage area fordetermining a location of another base station in deploying the network.Additional base stations can be deployed, though not shown for ease ofexplanation, to provide additional coverage across the map 100. In oneexample, sufficient base stations can be deployed to facilitate completeor nearly complete horizontal plane coverage for the map 100 usingmultiple coverage areas 104. However, other embodiments may simply coverair corridors that are commonly traveled by commercial airliners orother aircraft.

In addition, coverage area 104 can have an elevation aspect to provide asomewhat cylindrical coverage area. In this regard, aircraft flying atvarious altitudes can receive wireless communications from a basestation providing the coverage area 104 regardless of distance to thebase station. As described, the effective coverage area may not becylindrical in shape; however, the cylindrical coverage area 104 can bea minimum coverage area that the base station can be expected toprovide. Furthermore, additional base stations providing at least thecylindrical coverage areas can be positioned near coverage area 104,though not shown for ease of explanation, to provide additional coverageacross the map 102.

Base station antennas may be used in a first antenna array to provide acoverage area that expands to a desired elevation (and beyond) subjectto a vertical beam width projected by the antenna over a distance awayfrom the base station. Such antennas, however, may not allow for fullycovering the desired elevation near the antennas, and thus aircrafttraveling at higher elevations near the base station may not be able tocommunicate with the base station to receive ATG wirelesscommunications. Thus, to achieve at least the cylindrical coverage area104, such that coverage is provided at high elevations near the basestation, a second antenna array can be used to provide additional ATGwireless communication in the elevation space near the base station thatlacks coverage from the base station antennas. Moreover, to the extentcoverage gaps remain from the first and second antenna arrays,additional patch antennas can be employed to provide ATG wirelesscommunication as well (e.g., directly overhead of the base stationantennas). It is to be appreciated that other antennas can be used inthe antenna arrays instead of conventional base station antennas, solong as ATG wireless communications are provided at a desired elevationout to a desired radial distance from the base station.

FIG. 2 illustrates an example system 200 that uses multiple antennas ata base station to provide at least a cylindrical coverage area. System200 includes a base station 202 having multiple antennas 204, 206, 208,210, and 212 to facilitate providing wireless communications to aircraftwithin defined coverage areas. In one example, antennas 204 and 206 canform at least a portion of a first antenna array at the base station202. In one specific example, the antennas 204 and 206 project avertical beam width with a degree to provide first cell coverage areas220 and 230 extending substantially from the horizon up to a firstelevation angle away from antennas 204 and 206 to a predetermineddistance from the antennas 204 and 206. In one specific example,antennas 204 and 206 can have around a 5-10 degree vertical beam widthto facilitate providing coverage at a 45,000 feet (ft) altitude over acertain radial distance from the base station 202. Moreover, thoughshown as configured substantially parallel to base station 202, it is tobe appreciated that antennas 204 and 206 can have a small uptilt ordowntilt elevation to optimize long-range coverage up to normal flightaltitudes (e.g., 45,000 ft). Antennas 204 and 206 can provide respectivecoverage areas 220 and 230. In one example, antennas 204 and 206 can be,or can be similar to, conventional base station antennas except thatthey can provide coverage increasing in elevation as radial distanceincreases. For example, as depicted, the beam width of coverage areas220 and 230 extends at the first elevation angle to eventually reach45,000 ft and can continue achieving at least that altitude for at leasta predetermined distance (e.g., 100 miles), but does not cover apredetermined altitude (e.g., 45,000 ft) immediately near the basestation 202.

In this regard, a second antenna array, which includes at least antennas208 and 210 can be provided to fill coverage gaps near the base station202 and/or at higher altitudes nearer the base station 202. Antennas 208and 210 are configured at an uptilt elevation angle as compared toantennas 204 and 206 in the first antenna array, as depicted, to providea second cell coverage areas 222 and 232 extending at least from thefirst elevation angle of the first cell coverage areas 220 and 230 to asecond elevation away from antennas 208 and 210. In this example,antennas 208 and 210 provide the respective coverage areas 222 and 232to fill at least a portion of the coverage gaps of antennas 204 and 206up to a target altitude (e.g., 45,000 ft) near base station 202. In anycase, the first cell coverage areas 220 and 230, and the second cellcoverage areas 222 and 232, are concentric and can form an ATG cell forproviding ATG wireless communications over the target altitude.

In some examples, antennas 204 and 206 may be configured at an uptiltelevation angles such that their respective coverage areas 222 and 232converge within a certain distance above base station 202 to providecoverage up to 45,000 ft directly above base station 202, though somesmall altitudinal distance above base station 202 may not be covered. Inanother example, an additional patch antenna 212 is configuredperpendicularly to base station 202 to provide coverage area 240 to fillat least a portion of remaining coverage gaps between coverage areas 222and 232, thus forming another cell coverage area 240 of the ATG cell.Thus, to the extent second antenna array antennas 208 and 210 do notsufficiently fill coverage gaps near base station 202, patch antenna 212can further provide coverage closer still to base station 202. Forexample, patch antenna 212 can provide a cell coverage area concentricwith the first and second cell coverage areas at a point directly abovethe base station 202 at the desired altitude (e.g., 45,000 ft). In thisregard, antennas 204, 208, and 212 provide overlapping concentric cellsto result in continuous vertical coverage over an azimuth defined by theantennas to form the ATG cell. Antennas 206, 210, and 212 similarlyprovide concentric cells to form the ATG cell.

Though two antenna arrays (e.g., the first array with antennas 204 and206, and the second array with antennas 208 and 210), are shownproviding coverage at opposite directions (e.g., at a 180 degreedifference) in this two dimensional view of the base station 202, it isto be appreciated that additional antenna arrays can be configuredaround base station 202 in the respective antenna arrays to providesimilar altitudinal coverage in additional directions (e.g., at 60degree, 90 degree, etc. intervals) depending on the coverage azimuth ofa given antenna. In this regard, each antenna array can provide a sectorof coverage in a multi-sector configuration. Furthermore, in an example,base station 202 can instead include a single antenna array withomnidirectional antennas each configured to provide substantiallycircular coverage at a respective elevation angle in a single sectorconfiguration. In other words, for example, concentric cell coverageareas may be defined such that substantially donut shaped radiationpatterns are radiated from an antenna array with at least one suchpattern covering lower elevations and another pattern covering aconcentrically located area at higher elevations. With the use of apatch antenna to cover directly above the array, a continuous cylinderof coverage may be defined out to a predetermined range and up to apredetermined altitude using concentric cell coverage areas.

In addition, rather than employing multiple antennas in an antenna arrayat a given base station, in an example, antennas of neighboring basestations can be configured to provide a given elevation range ofcoverage. For example, a first base station can have one or moreantennas configured to provide coverage from the horizon up to a firstelevation angle (e.g., similarly to antennas 204 and 206). A second basestation located beyond the coverage range of the first base station canprovide one or more antennas configured at an uptilt angle to providecoverage from the first elevation angle to a second elevation (e.g.,similarly to antennas 208 and 210), and so on. The resulting coveragepattern effectively overlaps lower altitude cylinders of cell coveragewith higher altitude cylinders of coverage, and can thus achieve fullcoverage up to the predetermined altitude over a deployment area.

Moreover, though the first antenna array and second antenna array caninclude multiple antennas installed at the specific locations on basestation 202, in one example only one perpendicular patch antenna 212 maybe needed to cover an area centered above base station 202. In any case,at least the cylindrical coverage area 104, depicted previously, can beachieved up to 45,000 ft (or other altitudes) by the multiple antennas204, 206, 208, 210, 212, and/or other antennas of base station 202. Inthis example, antennas at varying uptilt (or downtilt) angles achievethe needed elevation near the base station to provide coverage in highaltitudes around the base station 202, and antennas at variouscircumferential positions around the base station provide the neededazimuth to provide coverage over a radial distance.

It is to be appreciated, for example, that antennas 204 and 206 canprovide coverage at further distances on the horizontal plane due to amore concentrated signal, and thus effective coverage of coverage areas220 and 230 can continue for distances beyond those for coverage areas222 and 232. Accordingly, base stations, such as base station 202 can bedeployed based on the radial distance of coverage provided by respectiveantennas 204 and 206 of the first antenna array to provide adjacent oroverlapping cylindrical coverage areas at the desired altitude, andrespective second antenna array antennas 208 and 210, or patch antenna212, at each of the base stations can provide needed coverage near thebase stations to achieve the desired altitude. Moreover, in one example,base station 202 can employ a radio switch to alternate between usingantennas on the first antenna array, such as antennas 204 and 206,antennas of the second antenna array, such as antennas 208 and 210,and/or patch antennas, such as antenna 212, to conserve radio resources,mitigate potential interference between the concentric cells, etc.

FIG. 3 illustrates a top view of example base station deployments 300for providing concentric cells to facilitate continuous ATG wirelesscoverage at high altitudes for at least a predetermined distance fromthe base stations. For example, cell coverage areas 302, 304, and 306are respectively provided by base stations 312, 314, and 316. The cellcoverage areas 302, 304, and 306 are clover shaped based on the azimuthand position of the antennas on base stations 312, 314, and 316, whichare shown at 90 degree intervals around the base stations 312, 314, and316, in this example, and provide at least a 90 degree azimuth, in thedepicted example. As described, the cell coverage areas 302, 304, and306 can have a vertical beam width that allows the cell coverage areasto achieve an elevation as projected from the antennas of base stations312, 314, and 316.

This configuration, however, can provide coverage gaps at certainaltitudes for a radial distance from the base station to the point wherethe cell coverage areas reach the desired altitude. In this regard, asdescribed, additional antennas are configured at base stations 312, 314,and 316 to deploy concentric cell coverage areas 322, 324, and 326 thatprovide coverage in the altitudinal coverage gaps of cell coverage areas302, 304, and 306, respectively, to define an ATG cell. As described,the additional antennas are configured at higher uptilt elevation anglesthan those providing cell coverage areas 304, 304, and 306 such thatcell coverage areas 322, 324, and 326 cover higher altitudes near basestations 302, 304, and 306, but not necessarily at the radial distanceof cell coverage areas 302, 304, and 306. Additional antennas can beprovided where further gaps exist (e.g., an antenna perpendicular to thegiven base station 312, 314, or 316, that provides coverage directlyabove the base station as well). Moreover, multiple additional ATG cellscan be similarly configured to provide continuous coverage over a targetarea at least at the desired altitude.

Moreover, in an example, the antennas providing cell coverage areas 322,324, and 326 can be rotated at a rotational offset from the antennasproviding cell coverage areas 302, 304, and 306 (e.g., by 45 degreeswhere antennas are positioned at 90 degrees) to mitigate the clovershaped coverage pattern. Coverage areas 322, 324, and 326 are depictedas covering a significantly smaller distance than coverage areas 302,304, and 306; it is to be appreciated that this is shown to indicate thealtitudinal coverage deficiency of cell coverage areas 302, 304, and 306that is filled by coverage areas 322, 324, and 326. Indeed, cellcoverage areas 322, 324, and 326 can have a coverage area distancesimilar to cell coverage areas 302, 304, and 306 or at least greaterthan that depicted in FIG. 3 . In this regard, rotating the antennasproviding cell coverage areas 322, 324, and 326 (e.g., antennas 208 and210 in FIG. 2 ) to offset from antennas providing cell coverage areas302, 304, and 306 (e.g., antennas 204 and 206 in FIG. 2 ) by around 45degrees (or at least at a number of degrees substantially half of thenumber of degrees separating the antennas around the base station)allows the antennas providing coverage areas 322, 324, and 326 to bedirected between the antennas providing coverage areas 302, 304, and 306such to fill coverage gaps between the antennas.

FIG. 4 illustrates a functional block diagram of a base station 400 inan example embodiment. In this regard, for example, the base station 400may include processing circuitry 402 that may be configurable to performcontrol functions in accordance with example embodiments. The processingcircuitry 402 may provide electronic control inputs to one or morefunctional units of an aircraft for providing ATG wirelesscommunications thereto. The processing circuitry 402 may be configuredto perform data processing, control function execution and/or otherprocessing and management services according to an example embodiment.

In some examples, the processing circuitry 402 may be embodied as a chipor chip set. In other words, the processing circuitry 402 may compriseone or more physical packages (e.g., chips) including materials,components and/or wires on a structural assembly (e.g., a baseboard).The structural assembly may provide physical strength, conservation ofsize, and/or limitation of electrical interaction for componentcircuitry included thereon. The processing circuitry 402 may therefore,in some cases, be configured to implement an embodiment of the disclosedsubject matter on a single chip or as a single “system on a chip.” Assuch, in some cases, a chip or chipset may constitute means forperforming one or more operations for providing the functionalitiesdescribed herein.

In an example embodiment, the processing circuitry 402 may include oneor more instances of a processor 404 and memory 406 that may be incommunication with or otherwise control a transceiver 408. Theprocessing circuitry 402 may be embodied as a circuit chip (e.g., anintegrated circuit chip) configured (e.g., with hardware, software or acombination of hardware and software) to perform operations describedherein. However, in some embodiments, the processing circuitry 402 maybe embodied as a portion of an on-board computer. The transceiver 408may include one or more mechanisms for enabling communication withvarious devices. In some cases, the transceiver 408 can include deviceor circuitry embodied in either hardware, or a combination of hardwareand software that is configured to receive and/or transmit data from/toaircraft or other devices in communication with the processing circuitry402. Thus, for example, the transceiver 408 may allow for communicationvia different antennas, such as a first antenna 410 and a second antenna412.

In an example embodiment, the processing circuitry 402 may be configuredto control configuration or operation of one or more instances of thetransceiver 408 to facilitate operation of the first antenna 410 andsecond antenna 412 via one or more radios 414. In one example, radio 414includes a switch 416 to switch between activating first antenna 410 andsecond antenna 412. In another example, though not depicted, theantennas 410 and 412 can use independent radios, and/or can transmitsignals concurrently. In any case, processing circuitry 402 can usetransceiver 408 to provide cell coverage via communications using firstantenna 410 and/or second antenna 412 to provide concentric cellcoverage areas, as described. Transceiver 408 can employ additionalantennas (not shown) to provide additional concentric cells to achieve acylindrical coverage area. In this regard, the first antenna 410 can bepart of a first antenna array, and the second antenna 412 can be part ofa second antenna array. One or more patch antennas can be controlled bytransceiver 408 as well (and/or can be switched using radio 414), thoughnot shown.

The processor 404 may be embodied in a number of different ways. Forexample, the processor 404 may be embodied as various processors, suchas one or more of a microprocessor or other processing element, acoprocessor, a controller or various other computing or processingdevices including integrated circuits such as, for example, anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or the like. In an example embodiment, the processor402 may be configured to execute instructions stored in the memory 406or otherwise accessible to the processor 404. As such, whetherconfigured by hardware or by a combination of hardware and software, theprocessor 404 may represent an entity (e.g., physically embodied incircuitry—in the form of processing circuitry 402) capable of performingoperations according to embodiments of the present invention whileconfigured accordingly. Thus, for example, when the processor 404 isembodied as an ASIC, FPGA or the like, the processor 404 may bespecifically configured hardware for conducting the operations describedherein. Alternatively, as another example, when the processor 404 isembodied as an executor of software instructions, the instructions mayspecifically configure the processor 404 to perform the operationsdescribed herein.

In an example embodiment, the processor 404 (or the processing circuitry402) may be embodied as, include or otherwise control the operation ofthe base station 400, as described herein. As such, in some embodiments,the processor 404 (or the processing circuitry 402) may be said to causeeach of the operations described in connection with the base station 400in relation to operation of the base station 400 by directing componentsof the transceiver 408 to undertake the corresponding functionalitiesresponsive to execution of instructions or algorithms configuring theprocessor 404 (or processing circuitry 402) accordingly.

In an exemplary embodiment, the memory 406 may include one or morenon-transitory memory devices such as, for example, volatile and/ornon-volatile memory that may be either fixed or removable. The memory406 may be configured to store information, data, applications,instructions or the like for enabling the processing circuitry 402 tocarry out various functions in accordance with exemplary embodimentsdescribed herein. For example, the memory 406 could be configured tobuffer input data for processing by the processor 404. Additionally oralternatively, the memory 406 could be configured to store instructionsfor execution by the processor 404. As yet another alternative, thememory 406 may include one or more databases that may store a variety ofdata sets related to functions described herein. Among the contents ofthe memory 406, applications may be stored for execution by theprocessor 404 in order to carry out the functionality associated witheach respective application. In some cases, the applications may includeinstructions for recognition of various input signals related tocomponent status or operational parameters and, if necessary, applyingtiming control, encryption, channel control and/or the like associatedwith handling the reception of such signals. The applications mayfurther include instructions for operational control of the base station400, as described above.

Referring to FIG. 5 , a methodology that can be utilized in accordancewith various aspects described herein is illustrated. While, forpurposes of simplicity of explanation, the methodology is shown anddescribed as a series of acts, it is to be understood and appreciatedthat the methodology is not limited by the order of acts, as some actscan, in accordance with one or more aspects, occur in different ordersand/or concurrently with other acts from that shown and describedherein. For example, those skilled in the art will understand andappreciate that a methodology could alternatively be represented as aseries of interrelated states or events, such as in a state diagram.Moreover, not all illustrated acts may be required to implement amethodology in accordance with one or more aspects.

FIG. 5 illustrates an example methodology 500 for providing cellcoverage areas to facilitate ATG wireless communications at desiredelevations over a radial distance. At 502, a signal can be transmittedusing a first antenna array configured to form a first cell coveragearea extending to a first elevation angle. For example, the firstantenna can be installed substantially parallel to the base station (orat a small uptilt or downtilt angle) for projecting signals across aradial distance from the base station in a horizontal plane. The firstantenna array can be configured to transmit the signals to have anincreasing vertical beam width, which can extend from the horizon at thefirst elevation angle and reach a desired elevation at a given distance.This may, however, result in a coverage gap up to the desired elevationfor a radial distance from the base station to the point where the firstantenna array signals reach the desired elevation.

Thus, at 504, additional signals can be transmitted using a secondantenna array configured at an uptilt elevation angle to a secondelevation. For example, the second antenna array can be configured atthe location of antennas in the first antenna array, but can be angledupward by a certain tilt to fill the coverage gap at the desiredelevation between the base station and the point where the first antennaarray signals reach the desired elevation. The second antenna array canbe configured to transmit at another vertical beam width from at leastthe first elevation angle towards a second elevation angle. It is to beappreciated that additional patch antennas can be provided as well(e.g., one substantially perpendicularly to the base station to fill anyremaining coverage gap centered above the base station).

Optionally, at 506, a radio can be switched to transmit over the secondantenna array. Switching between antennas using a single radio canconserve radio resources, mitigate interference between the variouscoverage cell signals, and/or the like.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Moreover, although the foregoing descriptions and the associateddrawings describe exemplary embodiments in the context of certainexemplary combinations of elements and/or functions, it should beappreciated that different combinations of elements and/or functions maybe provided by alternative embodiments without departing from the scopeof the appended claims. In this regard, for example, differentcombinations of elements and/or functions than those explicitlydescribed above are also contemplated as may be set forth in some of theappended claims. In cases where advantages, benefits or solutions toproblems are described herein, it should be appreciated that suchadvantages, benefits and/or solutions may be applicable to some exampleembodiments, but not necessarily all example embodiments. Thus, anyadvantages, benefits or solutions described herein should not be thoughtof as being critical, required or essential to all embodiments or tothat which is claimed herein. Although specific terms are employedherein, they are used in a generic and descriptive sense only and notfor purposes of limitation.

What is claimed is:
 1. An air-to-ground (ATG) wireless communicationnetwork comprising: a plurality of base stations deployed to definethree dimensional coverage up to a predetermined altitude, wherein thebase stations comprise: a first antenna array comprising a first set offour antennas installed at four respective different 90 degree sectorsto define 360 degrees of coverage around the base station between thehorizon and a first elevation angle, the first antenna array forming afirst cell coverage area; and a second antenna array configured at anuptilt elevation angle, the second antenna array comprising a second setof four antennas installed at four respective different 90 degreesectors to define 360 degrees of coverage around the base station toform a second cell coverage area.
 2. The network of claim 1, wherein thesecond cell coverage area extends above the first elevation angle and isconcentric with the first cell coverage area.
 3. The network of claim 2,wherein the first cell coverage area and the second cell coverage areaeach extend away from the base stations substantially a same radialdistance.
 4. The network of claim 3, wherein the radial distance is atleast 100 miles.
 5. The network of claim 1, wherein the first antennaarray and the second antenna array each employ different respectiveradios to enable the first and second antenna arrays to transmit signalsconcurrently.
 6. The network of claim 1, wherein the first and secondcell coverage areas overlap each other at an overlap region that extendsradially away from the base stations and that extends in elevation asradial distance from the base stations increases.
 7. The network ofclaim 1, wherein the second antenna array is configured to transmitsignals at a higher elevation and vertical beam width than the first setof four antennas of the first antenna array at a given radial distancefrom the base stations.
 8. The network of claim 1, wherein the basestations are geographically separated to overlap each other to providecomplete horizontal plane coverage of a geographic area.
 9. The networkof claim 1, wherein each of the base stations of the network includes acorresponding instance of the first antenna array and the second antennaarray and a sky cell providing coverage directly above the each of thebase stations.
 10. The network of claim 1, wherein the second cellcoverage area extends from the first elevation angle to a secondelevation angle.
 11. The network of claim 10, wherein the at least oneof the base stations further comprises a patch antenna providingcoverage from the second elevation angle to a zenith directly above theat least one of the base stations.
 12. The network of claim 1, whereinthe predetermined altitude is about 45,000 ft.
 13. The network of claim1, wherein the first and second cell coverage areas each cover a rangeof altitudes that increase as radial distance from the base stationsincreases.
 14. The network of claim 13, wherein the second cell coveragearea extends over a first range of altitudes that is overlaid above asecond range of altitudes associated with the first cell coverage area.15. The network of claim 1, wherein the first antenna array and thesecond antenna array are configured such that the first cell coveragearea and the second cell coverage area are concentric over a similarazimuth and combine to provide full coverage up to the predeterminedaltitude out to a radial distance defined from the at least one of thebase stations.
 16. The network of claim 1, wherein each of the first andsecond coverage areas has a clover shape.
 17. The network of claim 1,wherein each of the first and second coverage areas has a cylindricalshape.
 18. The network of claim 1, wherein each of the first and secondcoverage areas has a same shape.